Automatic rafter square



Patented Nov. 6, 1951 UNITED sTATEs PATENT OFFICE AUTOMATIC RAFTER SQUARE Herbert Cowan Heiskell, J oplin, Mo.

Application January 31, 1951, Serial No. 208,710

3 Claims.

This invention relates to a rafter square. More particularly, the invention has reference to a rafter square of novel design, embodying an adjustable ruling blade which, when adjusted to the selected position, permits all necessary cuts to be made upon the rafters with ease and speed, with only one adjustment for both cuts of the rafter.

One important object of the present invention is to provide a rafter square of the Character described which will, when set, be automatically adjusted for proper marking and cutting of raftersfto selected angles, without the necessity of the user yknowing any more, in advance, than the width of the house and the desired rise to be given toV the raf ters.

Another important object is to provide a device of the character described the setting of which can be 'effeoted simply, quickly, and with complete accuracy. No computations are necessary, since the lengthof the rafter is given automatically.

Another important object is to provide a device as -stated which is readily usable by unskilled laborers.

Still another object is to provide a tool as stated which can be manufaotured at relatively low cost, and which will be durable and so formed as not to readily get out of order.

i With the foregoing and other objects in view which Will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts, hereinafter more fully described and pointed out in the claims, it being understood that changesmay be made in the material and construction and arf rangement of parts without departing from the spirit of the invention as claimed.

Referring to the drawings Fig. 1 is a top plan view of a rafter square formed in accordance With the present invention.

Fig. 2 is an enlarged top plan view of a fragmentary portion of one arm ofV the square.

Fig. 3 is a longitudinal section through said fragmentary portion of the arm.

Fig. 4 is an enlarged section on line 4-4 of Fig. 1.

Fig. 5 is a view similar to Fig. 1 on a reduced scale, showing a second position of the rule, portions of the rule being broken away.

Fig. 6 is an inverted perspective view of one of the guides mounted on the rule.

Referring to the drawings in detail, the rafter i square constituting the present invention embodies a conventionally formed square including the rigidly connected arms I and 2 at right angles 2 i to each other, said square being graduated along its outer edge in twelfths of an inch.

` Mounted upon the arm is a fiat sleeve 3 slidable upon the arm, thus having the plates 4 rigidly connected to said sleeve in spaced relation, each plate 4 being formed with an upstanding bracket 5. The brackets have arouate slots 6 for a purpose to be made apparent.

In the space between the brackets is disposed one end ,of a solid or channeled lock member 1 pivotally connected to the brackets as at 8. The member is shown as channeled in the present instance, but it could be solid if so desired. -Said end of the look member 'l is provided with a: cam

surface 9. l ,V

The lock member 1 overlies a looking bar |0 rigidly connected by rivets I I to the fiat sleeve |2 also slidable upon the arm l. A spacer plate |3 is interposed between the looking bar IO'and th sleeve l2.

Centrally of the looking bar H), there is lformed therein a pin-receiving opening |3', and at its other or free end there is another pin-receiving opening |4 reoeiving the L-shaped pin I that extends through the slots 6.

The lock member l, When adjusted to one position, allows'the looking bar IO to spring upwardly at' its free end. This releases, for adjustment relative to the square arm I, one end portion of a ruling blade |6 one longitudinal edge of which may be reinforced by a channeled member H. The ruling blade |6 is of transparent 'plastic material. c i

p As will be noted, the other end portion of the ruling blade underlies another` looking bar?` i8 formed like the looking bar I. The bar l8 is rigidly seoured at one end to a sleeve 'I9 slidable upon the arm 2, and the other end of the bar 18 Springs upwardly between brackets 39 mounted upon a sleeve 20' slidable upon the arm 2.

A solid or channeled cam type looking member 2 I, Operating similarly to the member 1, is pivotally connected to and between the brackets 20,'

and controls the bar i 8 in the same manner that the member l controls the bar IO.

An L-shaped pin 22 is insertible in an opening 22' formed adjacent the free end of the bar |8, said opening corresponding to the opening H of the bar IO. Alternatively, the pin 22 is insertible in an intermediate opening 23 corresponding to opening 13.

In use, the pins |5 and 22 can be positioned either in the center openings l3' and 23, or in the end openings |4 and 22'. In the centered position of the bars IO and [8 it becomes possible steel square.

various sizes. lumber; line 21 refers to`2'I x lumber; line to make use of the corner of the square. The cam lock members 1 and 2| are now swung up- Wardly so as to permit upward swinging of the free ends of the bars IO and 18. This increases the space between said bars and the square arms and 2 and permits free adjustment of the ruling blade IB, which in effect has 'a floating mounting upon the arms I and 2.

After the end portions of the ruling blade have been adjusted to a Vdesired position, the cam lock members 'I and 21 are swung downwardly,

causing the members I 8 and IE] to be pressed downwardly toward the arms I and 2, thus to engage the end portions of the ruling blade l 'and hold said ruling blade in a selected position of adjustment.

There is no possibility of the end portions of the ruling blade slipping out of a desired location of adjustment, as the cams prevent movement of the slides that slide on both arms of the The transparent rule when forced against the respective arms of the square, and fixed in proper position for any certain pitch of irafter, 'remains accurate.

Thus, it.may be noted that assuming that the square is marked in twelfths, the length and angle of the rafters is automatically determined by merely setting the plastic rule.

Thereafter, the ruling blade Will, when it is positioned against the steel square and the bars 3|8'and i O, be automatically set for the particular angle of rafters to be cut, and the rafters can be marked and cut as desired, with but this one adjustment.

The ruling blade is provided with 'a pair of slid- H able sleeve guides 24 at opposite ends. These are fplace'don both ends or in the middle of the plastic rule, depending flanges 25 engageable against 'the same sides of a length of Wood to be marked.

When the ruling blade is in the position of Fig. 1, the guides can if desired be used on the center portion of the ruling blade.

With further reference to the ruling blade, this is provided with parallel line markings 26, 21, 28, 29 and 30. These lines provide the length at the ridge cut from heel to comb for rafters of Thus, line 26 refers to 2" x 12" 28 refers to 2" x 8 lumber; line 29 refers to 2" x 6" lumber; and line 30 refers to 2" x 4 lumber.

The ruling blade, further, is graduated by transverse lines as at 3| there being twenty-four -saidilines to each inch.

What is claimed is: 1. A rafter square including a square member `includingrigidly connected arms at right angles to each other, a ruling blade extending angularly across said arms and having a floating mounting upon said arms, slide members slidable along the 'respective arms, locking bars mounted upon the slide members, and means for pressing' the locking bars against the respective end portions of the ruling blade to hold the ruling blade in selected positions to which it is adjusted.

2. A rafter square including a square member having 'arms rigidly connected and disposed at right angles to each other, a pair of sleeves mounted for sliding movement upon each of said arms, a locking bar loosely connected at one end to one-sleeve of a pair of'sleeves, the other ends of the locking bars having a solid riveted connection to the other sleeves of the respective .pairs of sleeves, said other loose ends of the lock- .ingl bars .adapted to swing upwardly, lock members mounted upon certain of said sleeves above the feed ends of said locking bars, said lock members adapted to force the locking bars downwardly against the spring action thereof, and a rul- .ing blade having a fioating mounting beneath the respective arms, said ruling blade having end portions underlying the respective bars and locked by the locking bars, said end portions of :the ruling blade being adapted to be engaged between the locking bars and the arms of the square member to clamp the end portions 'of the ruling blade in selected positions.

3. A rafter square including a pair-of arms rigidly connected at right angles to each other, a pair of sleeves slidable upon'each of said arms, a locking bar rigidly connected at one end to one sleeve of each pair of sleeves, the other end Vof each locking bar being springable upwardly-above the other sleeve -of each pair of sleeves, `lsaid locking bars having openings *intermediate their ends and at their ends, a pin insertablein said openings and constituting a stop pin, a transparent ruling blade under said locking bars fioating or movable upon the respective arms, and a solid orchanneled locking memberpivotally connected to one sleeve of each pair of sleeves above the free end of the locking bar, said-channeled locking member having a cam surface at one end, said cam surface being adapted to engage the free end of each locking bar to force said locking bar downwardly in the directionof the arm underlying the locking-bar, thus to clamp the end portions of the ruling blade 'in selected positions of 'adjustment upon the arms, saidpins constituting stops changing said positions `of sleeves to make use of corner of square'by .clamping ruling blade With end instead of center lof locking bar.

HERBERT C. HEISKELL.

Name Date Ware Dec. v26, I944 Number 

